In CN101891675B titled “METHOD FOR PRODUCING 6-CHLORO-2-TRICHLOROMETHYLPYRIDINE”, the method comprises the following steps: (1) preparing 2-methylpyridine into solution by Using part of a solvent, adding the residual solvent into a reaction kettle and feeding excessive chlorine gas, then continuously adding 2-methylpyridine solution into the reaction kettle to perform chlorination reaction at temperature of 130-205° C., and when the content of 6-chloro-2-dichloromethylpyridine is detected by GC to be smaller than or equal to 0.5%, stopping the reaction to obtain a 6-chloro-2-trichloromethylpyridine crude product; and (2) purifying the 6-chloro-2-trichloromethylpyridine crude product in step (1) by adopting a distillation method to obtain a 6-chloro-2-trichloromethylpyridine product, wherein the solvent is selected from a group consisting of halogenated or nitrated aromatic compounds, and the ratio of the total weight of the solvent to the weight of 2-triethylpyridine is 0.1-10:1.
The disadvantage of this method is that the selectivity of chlorination reaction to chloro-6-trichloromethylpyridine is not good, components such as isomers and pentachloromethylpyridine in chloride are too many to be separated through distillation, and the amount of produced tar is too high.